Fortunately, the starting pitcher appears to have just a mild right hamstring injury.

"Clay strained his right hamstring covering first base," said manager John Farrell. "There's no timeframe yet. He's day to day. He'll get re-evaluated tomorrow and then we'll have a better read on how many days he's going to need treatment."

The injury happened in Boston's first official team workout.

"It was towards the end of the round," Buchholz said. "Just a matter of doing all the sprints yesterday and being a little tight, I guess. Maybe I didn't stretch as much as I needed to, but lesson learned. I'll be stretching every day now, as much as I can. They said it's minimal, maybe five days or so. I'll be able to re-evaluate tomorrow, see what the soreness is like and just go from there."

Farrell is cautiously optimistic that the injury won't have much of an impact on Buchholz's Spring Training.

"Well, it's not what we drew up, I know that," Farrell said. "We'll know more tomorrow in how many days he might miss, how many bullpen sessions he might have to make up. At this point, he wasn't scheduled to make his first appearance until probably day five of the game schedule. We're not going to pin ourselves to any time frames right yet until the training staff gets their hands on him tomorrow.

"It's a mild strain in the belly of the hamstring. It's not the connective areas either up underneath the buttock or near the knee. In terms of the placement of it, it's probably the best that you could hope for in this situation. It's a matter of treatment and ultimately strength testing. And there will be some functional tests before we get him back on the field."